Thursday, March 16, 2006

Chem Mater:Effect of Sodium Doping in -Tricalcium Phosphate on Its Structure and Propertie

- 31P-23Na REDOR experiments

Chem. Mater., 18 (6), 1425 -1433, 20

Effect of Sodium Doping in -Tricalcium Phosphate on Its Structure and Properties
Laetitia Obadia, Philippe Deniard, Bruno Alonso, Thierry Rouillon, Stéphane Jobic, Jérôme Guicheux, Marion Julien, Dominique Massiot, Bruno Bujoli,* and Jean-Michel Bouler

Abstract: For the preparation of -TCP and biphasic calcium phosphates (BCPs, mixtures of hydroxyapatite and -TCP), the presence of sodium in the reaction medium results in the incorporation of sodium in the -TCP network, by substitution of some calcium sites. Accordingly, a decrease of the unit cell volume of -TCP was observed with increasing sodium substitution. The distribution of sodium in the -TCP structure, as a function of the amount incorporated, was probed using 31P and 23Na MAS NMR and 31P{23Na} REDOR experiments. It was shown that an estimation of the sodium content in -TCPs could be obtained from the modeling of their 31P MAS NMR spectra. Moreover, the incorporation of sodium in -TCPs results in improved mechanical properties, without affecting the biocompatibility of the ceramics.

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